Combining real-time and batch mode logical address links

ABSTRACT

Systems and methods for displaying Internet content associated with television programming. Content associated with a program included in the television programming is automatically displayed by a set top box. Before the broadcast of a program, listing information or EPG data is stored at the set top box. The listing information includes batch mode logical addresses or links. During the program, a viewer is notified about the link, and the content may be accessed and displayed concurrently with the program. In addition, real-time logical addresses or links, which are embedded in the program, may be extracted and the viewer is notified of these links. If both the real time and batch links are available, a determination is made according to pre-defined rules regarding which link is brought to the attention of the viewer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/216,250, filed on Aug. 31, 2005, and entitled “COMBING REAL-TIME ANDBATCH MODEL LOGICAL ADDRESS LINKS”, which is a continuation of U.S. Pat.No. 6,990,678, issued on Jan. 24, 2006, and entitled “COMBININGREAL-TIME AND BATCH MODE LOGICAL ADDRESS LINKS”, which is a continuationof U.S. Pat. No. 6,215,483 issued on Apr. 10, 2001, and entitled“COMBINING REAL-TIME AND BATCH MODE LOGICAL ADDRESS LINKS”. All of theforgoing applications and patents are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The invention relates generally to the integration of broadcasttelevision programming with content from the Internet, World-Wide Web,Intranet, and/or other remote or local resources. More specifically, theinvention relates to the reception of logical address links in advanceof a television program and the combination of such links with thosethat may be received in real-time during a television broadcast via thevertical blanking interval.

2. The Relevant Technology

The World-Wide Web (the Web) is a collection of formatted hypertextpages located on numerous computers around the world that are logicallyconnected by the Internet. The Web has become a valuable resource forinformation relating to almost any subject, including business, travel,education, and entertainment, to name just a few. Many Web sites includecontent relating to popular television programs, specific episodes, andtheir characters, for example. Further evidence of the Web's commercialimportance is the fact that Uniform Resource Locators (URLs) have begunto appear on billboards, in newspaper and other print advertisements,and in the credits of TV programs and movies.

Traditionally, individuals have accessed Internet content from personalcomputers (PCs) by way of programs, such as Web browsers, that provide agraphical user interface to the Web. However, the introduction ofInternet terminals, such as those pioneered by WebTV Networks, Inc., theassignee of the present invention, has made the Web accessible to alarger segment of the population by providing access to the Web withoutthe use of a personal computer. These Internet terminals (also commonlyreferred to as set-top boxes) provide individuals with access to Webpages using an ordinary television (TV) set as a display and a remotecontrol or wireless keyboard for user input.

Currently, while Internet content may be identified by a TV program orcommercial, in order to view such Internet content, the TV viewer mustmanually key the URL into his/her Web browser or Internet terminal. Itwould be desirable to provide a more convenient mechanism forintegrating broadcast television programming with the Web to facilitatethe retrieval and viewing of Internet content concurrently with thetelevision broadcast or at a later time at the option of the viewer. Inparticular, it would be desirable to provide a mechanism for notifyingthe viewer of the existence of Internet content relating to and/orassociated with the current TV program or commercial, for example, andallowing such content to be automatically displayed upon request by theviewer.

BRIEF SUMMARY OF THE INVENTION

A method and apparatus are described for receiving logical address linksin advance of a television program and combining such links with thosethat may be received in real-time during a television broadcast.According to one aspect of the present invention, content associatedwith a television CIV) program may be automatically displayed by aclient system. Prior to broadcast of a TV program, TV listinginformation is stored in the client system. The TV listing informationincludes one or more logical addresses that identify content, such asInternet content. The client system alerts the viewer of the existenceof an active logical address associated with the current TV program byproviding a visual indication. After the visual indication has beenselected by the viewer, the client system displays the contentidentified by the logical address.

According to another aspect of the present invention, links to Internetcontent relating to a TV program may be provided to an Internetterminal. TV listing information, including one or more batch modeUniform Resource Locators (URLs) associated with a TV program, isreceived from a server. The TV listing information also includes one ormore of the following: program start times, program end times, and timesat which the one or more batch mode URLs are active. The TV listinginformation is stored in the Internet terminal. Subsequently, one ormore real-time URLs are received embedded in a video signal associatedwith the TV program. The Internet terminal determines which of the oneor more real-time URLs and the one or more batch mode URLs to bring tothe attention of the user of the Internet terminal based upon a set ofpredefined rules.

Other features of the present invention will be apparent from theaccompanying drawings and from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 is a block diagram illustrating several clients connected to aserver system.

FIG. 2 is a diagram illustrating a client according to one embodiment ofthe present invention.

FIG. 3 is a block diagram illustrating exemplary functional units of aset-top box according to one embodiment of the present invention.

FIG. 4 is a flow diagram illustrating a method of transporting logicaladdress links according to one embodiment of the present invention.

FIG. 5 is a flow diagram illustrating logical address link receptionprocessing according to one embodiment of the present invention.

FIG. 6 conceptually illustrates how real-time logical address links andbatch mode logical address links may be combined according to oneembodiment of the present invention.

FIG. 7 is a flow diagram illustrating a method of combining real-timelogical address links and batch mode logical address links according toone embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A method and apparatus are described for receiving logical address linksin advance of a television program and combining such links with thosethat may be received in real-time during a television broadcast. Thelogical addresses may provide “links” to Internet, Web, or other localor remote content related or unrelated to a program being broadcast. Aform of logical address (also referred to as a resource locator)commonly associated with Web content is a Uniform Resource Locator(URL). A URL is a compact string representation of a location used toidentify an abstract or physical resource on the Internet. Of course,alternative means of uniquely identifying content may be employed. Forexample, it is appreciated that keys (e.g., database indices), networkaddresses (e.g., IP addresses), and other identification mechanisms,alone or in combination, may be employed to uniquely identify aresource. Therefore, while the term URL refers to a specific type ofcontent identifier used in connection with the Web, the terms logicaladdress and/or resource locator are used herein to refer tocontent/resource identification mechanisms generally.

At any rate, supplying links to Internet/Web content provides an easyand powerful way to bring the richness and interactive nature of theInternet to TV. Such links may be used by program producers, programsponsors, networks, local affiliates and other content providers to linkTV viewers to Web content specifically designed to complement what theviewers are watching on TV at a given time. According to one aspect ofthe present invention, a TV viewer may be notified about the existenceof a logical address associated with the current TV program. One or morelogical addresses associated with content (e.g., Internet content) maybe received and stored by a client, such as a PC or an Internetterminal. These logical addresses (referred to as batch mode logicaladdresses) may be received as part of TV listing information, such as anElectronic Programming Guide (EPG). When a logical address becomesactive, e.g., the TV program to which it relates is currently beingbroadcast or the current time is past a start time associated with thelogical address, then an icon or some other visual indication may bepresented to the viewer to notify the viewer of the availability ofcontent.

In addition to the batch mode logical addresses, other logical addressesmay be received in real-time embedded in a video signal associated withthe current TV program. Therefore, according to one another aspect ofthe present invention, a mechanism is provided for selecting among batchmode and real-time logical addresses based upon a set of predefinedrules. Real-time logical addresses may be embedded in a video signal inaccordance with an Electronic Industries Association (EIA) standardentitled, “Recommended Practice for Line 21 Data Services,” approvedSep. 20, 1994 (“EIA-608”) and an exemplary syntax described below.EIA-608 is incorporated herein by reference.

The present invention includes various steps, which will be describedbelow. The steps can be embodied in machine-executable instructions,which can be used to cause a general-purpose or special-purposeprocessor programmed with the instructions to perform the steps.Alternatively, the steps of the present invention might be performed byspecific hardware components that contain hardwired logic for performingthe steps, or by any combination of programmed computer components andcustom hardware components. Importantly, while embodiments of thepresent invention will be described with respect to viewing Web contenton an Internet terminal, such as the WebTV™ Internet terminal, certainaspects of the invention have equal application to various other TVviewing devices, such as personal computers equipped with TV tuners, andthe like.

Additionally, the method and apparatus described herein are equallyapplicable to other types of content that may be stored remotely orcontent that may be directly accessible to the viewing system (WebTV™ isa registered trademark of WebTV Networks, Inc. of Palo Alto, Calif.).For example, logical addresses embedded in a video signal may refer tocontent stored on a CD-ROM or other mass storage device, a company'sIntranet server, or other resource. Moreover, while various embodimentsof the present invention will be described with reference to an NTSCbroadcast video signal, aspects of the present invention are equallyapplicable to other broadcast TV systems, such as Phase Alternate Lines(PAL), Sequential Couleur Avec Memoire (SECAM), and the proposed HighDefinition Television (HDTV) standard. Finally, it is appreciated that avariety of transport mechanisms may be employed, including analog cable,digital satellite, digital TV, and cable TV.

System Overview

Aspects of the present invention may be included in an Internet systemterminal, such as the WebTV™ internet terminal, for providing a userwith access to the Internet. As will be discussed further below, theInternet system includes an Internet terminal (also referred to as anInternet System client) (“client”) and an Internet server (“server”). Auser of an Internet terminal generally accesses a server via adirect-dial telephone (POTS, for “plain old telephone service”), ISDN(Integrated Services Digital Network), or other similar connection, inorder to browse the Web, send and receive e-mail, and use various otherInternet system network services. Services provided by the Internetsystem network service, such as the WebTV network, are typicallyprovided by servers using software residing within the servers inconjunction with software residing within a client.

FIG. 1 illustrates a basic configuration of an Internet system networkin which one embodiment of the present invention may be implemented. Anumber of clients 1 are coupled to a modem pool 2 via direct-dial,bi-directional data connections 29, which may be telephone (POTS, i.e.,“plain old telephone service”), ISDN (Integrated Services DigitalNetwork), or any other similar type of connection. Other connectionmechanisms may be employed such as cable and satellite forward channels,for example. In any event, the modem pool 2 is coupled typically througha router, such as that conventionally known in the art, to a number ofremote servers 4 via a conventional network infrastructure 3, such asthe Internet. The Internet system also includes a server 5, whichspecifically supports the clients 1. The clients 1 each have aconnection to the server 5 through the modem pool and the Internet 3.Note that the modem pool 2 is a conventional modem pool, such as thosefound today throughout the world providing access to the Internet andprivate networks.

An Exemplary Client System

FIG. 2 illustrates an Internet system client (“client”) 1 known in theart. The client includes an electronics unit 10 (hereinafter referred toas “the set-top box 10”), an ordinary television set 12, and a remotecontrol 11. In an alternative embodiment of the present invention, theset-top box 10 is built into the television set 12 as an integral unit.In the embodiment depicted, the client 1 uses the television set 12 as adisplay device for displaying video data and a graphical user interface.The set-top box 10 is coupled to the television set 12 by a video link6. The video link 6 is an RF (radio frequency), S-video, compositevideo, or other equivalent form of video link.

The set-top box 10 includes hardware and/or software for receiving anddecoding a broadcast video signal 8, such as an NTSC, PAL, SECAM orother TV system video signal, and providing video data to the televisionset via video link 6. The set-top box 10 also includes hardware and/orsoftware for providing the user with a graphical user interface, bywhich the user can access various Internet system network services,browse the Web, send e-mail, and otherwise access the Internet. The userinterface includes means for notifying the user of the presence ofencoded data, such as URLs, embedded in the video signal. Thenotification may be audible, visual or a combination of the two. In oneembodiment, the notification comprises temporarily displaying an icon ina portion of the screen.

The client 1 may include both a standard modem and an ISDN modem, suchthat the communication link 29 between the set-top box 10 and the server5 can be either a telephone (POTS) connection 29 a or an ISDN connection29 b. The set-top box 10 receives power through a power line 7.

Remote control 11 is operated by the user in order to control the client1 in browsing the Web, sending e-mail, and performing otherInternet-related functions. The set-top box 10 receives commands fromremote control 11 via an infrared (IR) communication link. Inalternative embodiments, the link between the remote control 11 and theset-top box 10 may be RF or any equivalent mode of transmission.

Exemplary Client System Architecture

FIG. 3 is a block diagram illustrating internal features of the set-topbox 10. In this example, operation of the client 1 is controlled by aprocessing unit, such as central processing unit (CPU) 21, which iscoupled to an Application-Specific Integrated Circuit (ASIC) 20. The CPU21 executes software designed to implement various features of thepresent invention. ASIC 20 contains circuitry which may be used toimplement certain features provided by the client 1. ASIC 20 is coupledto an audio digital-to-analog converter (DAC) 25 which provides audiooutput to television 12. In addition, ASIC 20 is coupled to a videoencoder 26 which provides video output to television set 12. An IRinterface 24 detects IR signals transmitted by remote control 11 and, inresponse, provides corresponding electrical signals to ASIC 20. Astandard telephone modem 27 and/or an ISDN modem 30 are coupled to ASIC20 to provide connections 29 a and 29 b, respectively, to the modem pool2 and, via the Internet 3, to the remote servers 4. Note that theset-top box 10 also may include a cable television modem (not shown).

A TV interface 31 is coupled to ASIC 20 to receive broadcast videosignals, such as an NTSC video signal, and provide correspondingelectrical signals to ASIC 20, thereby allowing video data carried inthe broadcast video signal 8 to be presented to the viewer on the TV 12.The TV interface 31 also extracts other data that may be embedded in thevideo signal. The data so extracted, or a portion thereof, may bedisplayed concurrently with a television program. For example, in oneembodiment of the present invention, titles corresponding to logicaladdresses that have been inserted into a text mode data service or acaptioning data channel of line 21 of the VBI are extracted by the TVinterface 31 and displayed on the TV 12. An exemplary syntax fortransporting logical addresses in line 21 of the VBI is described below.

Also coupled to ASIC 20 is Read-Only Memory (ROM) 22, which providesstorage of program code for implementing application software to beexecuted by the set-top box 10. Note that ROM 22 may be a programmableROM (PROM) or any form of erasable PROM (EPROM) or Flash memory. Alsocoupled to ASIC 20 is Random Access Memory (RAM) 23. A mass storagedevice 28 may optionally be provided and coupled to ASIC 20.

The mass storage device 28 may be used to input software or data to theclient or to download software or data received over network connection29 or data embedded in broadcast signal 8. The mass storage device 28includes any suitable medium for storing machine-executableinstructions, such as magnetic disks, optical disks, and the like.

Logical Address Links

Having described an exemplary environment in which embedded logicaladdresses may be employed, logical address links, their syntax, andusage will now be discussed.

Generally, logical address links, such as TV Crossover-Links™, enableseamless integration of television programming and the Internet byallowing Internet content to be associated with a television broadcast(TV Crossover-Links™, is a trademark of WebTV Networks, Inc. of PaloAlto, Calif.). In one embodiment of the present invention, the client 1allows Web content and television programming to be concurrentlydisplayed as described in co-pending patent application Ser. No.09/087,354 entitled “Method and Apparatus for Displaying HypertextMark-up Language and Video Simultaneously” filed May 29, 1998 andassigned to the assignee of the present invention which is incorporatedherein by reference.

Importantly, associations between a television broadcast and Internetcontent may be performed in real-time or in batch mode. Real-timelogical address links are sent to the TV viewers client system during atelevision broadcast in line 21 of the VBI. In contrast, batch modelogical address links are delivered to the client system in advance ofthe television broadcast to which they relate. For example, batch modelogical address links may be downloaded from a Web server to the user'sclient system or delivered on CD-ROM or other computer readable medium.According to one embodiment, batch mode logical address links aredelivered as part of an electronic programming guide EPG) and may bemodified and/or supplemented with real-time logical address links. Whilereal-time logical address links are valid for a predetermined amount oftime after receipt by the client system, batch mode logical addresslinks typically define a time interval. For example, a batch modelogical address link may include a start time and an end time indicatingwhen the link is to be made available to the viewer.

Syntax for Logical Address Links

Logical addresses may be transmitted in one of the text service channelsof line 21, i.e., First Text Service (T1), Second Text Service (T2),Third Text Service (T3), or Fourth Text Service (T4), or one of thecaptioning data channels of line 21, i.e., Primary Synchronous CaptionService (CC1), Special Non-synchronous Use Captions (CC2), SecondarySynchronous Caption Service (CC3), or Special Non-synchronous UseCaptions (CC4), by using the following encoding format for logicaladdress strings on line 21 of the VBI:

<logical address> [attribute₁:value₁] [attribute₂:value₂] . . .[attribute_(n):value_(n)] [checksum]

The logical address (e.g., a URL) is enclosed in angle brackets. One ormore pairs of attributes and values may follow the logical address insquare brackets. Finally, a checksum follows the nth attribute/valuepair in square brackets. It is appreciated that delimiter charactersother than angle brackets and square brackets may be employed. However,it is important to avoid employing delimiters that are included in theURL character set. Additionally, it is preferable that the delimiter bepresent in both the standard EIA-608 character set and the US-ASCIIcharacter set to make logical address links relevant to the widest setof devices.

Attributes

Exemplary attributes include “type” and “name.” The type attributeindicates to what the content associated with the URL relates. Forexample, the content may be related to the current television program,to the broadcast network, or to one of the commercial sponsors of thecurrent TV program. Table 1 lists exemplary values that may beassociated with the type attribute.

TABLE 1 Meaning of Type Attribute Values Type Attribute Value Related toPROGRAM the current program NETWORK the broadcast network programSTATION the local station SPONSOR a commercial sponsor of the currentOPERATOR the service (e.g., cable or satellite) operator

The name attribute provides a concise tide for the resource identifiedby the logical address. It is preferable to associate a title with alogical address since the logical address itself doesn't always makeclear what the content of the identified resource is. For example, theURL http://www.nbe.com/tvcentral/shows/seinfeld/characters/index.htmlmight identify a web page on NBC's web site that describes frequentlyappearing characters on the Seinfeld television program. Therefore, forthe viewers' convenience, a value such as “Seinfeld Stars” may beassociated with the name attribute for this logical address link.Similarly, a web page relating to guest stars, such as the web pagelocated athttp://www.nbc.com/tvcentral/shows/seinfeld/characters/char2.html, mightbe associated with the name “Seinfeld Guest Stars.”

Various other attributes are contemplated by the assignee of the presentinvention. For example, a mechanism for purging old links may utilize anattribute that identifies a date or a date and time at which a logicaladdress link expires. In this manner, after the date indicated, logicaladdress links having an expires attribute may be purged from theclient's memory.

Importantly, attributes are optional and need not appear in anyparticular order. For purposes of illustration, exemplary logicaladdress links are listed below (note, however, the checksums have notbeen calculated):

<http://www.nbc.com/tvcentral/shows/seinfeld/characters/index.html>[name:Seinfeld Starts][A6F1]

<http://www.tvprogram.com> [type:program] [name TV Program] [C8C5]

<http://advsponsor.net> [type:sponsor] [name: Special Offer] [BFA0]

<http://madkad_network.com> [type:network] [1128]

<http://www.coolsite.com> [6C1D]

Importantly, it should be appreciated that logical addresses are notlimited to URLs and that URLs are not limited to the “http:” scheme.Therefore, the following would also be recognized as valid logicaladdress links:

<mailto:info@advsponsor.net> [type:sponsor] [5PDB]

<news:alt.tv.program][type: program][391B]

Checksum

A checksum is appended to the end of the logical address link in orderto detect data corruption that may occur during receipt or transmissionof the logical address link. Preferably, a two byte hexadecimal checksumis employed such as a checksum that would be produced by the standardTCP/IP checksum algorithm described in Request For Comments (RFC) 719,“Internet Protocol”, September 1981 which is incorporated herein byreference. According to one embodiment, the checksum is computed bypairing adjacent characters in the string (starting with the firstdelimiter) to form 16-bit integers. If there are an odd number ofcharacters, the final character is paired with a byte of zeroes. At anyrate, the checksum is computed such that the one's complement sum of allof the 16-bit integers plus the checksum equals the 16-bit integer withall 1 bits. That is, the checksum is the one's complement of the one'scomplement sum of the 16-bit integers. Advantageously, in this manner, agreat deal less errors go undetected than in previously suggested 7-bitchecksum schemes with only a negligible increase in the logical addresslink's overall length.

Transmission of Logical Address Links

Referring now to FIG. 4, a flow diagram illustrating a method oftransporting logical address links according to one embodiment of thepresent invention is illustrated. In this embodiment, logical addresslink data to be inserted by a content provider, e.g., a programproducer, broadcaster, affiliate, cable or satellite provider, isinserted into upstream video (the source of video onto which the newdata will be encoded). At step 410, upstream video data is received froma previous point in the video signal distribution path. At step 420, adetermination is made as to whether or not the current distributionpoint has one or more logical address links that are to be associatedwith the current TV program being transmitted. If not, processingcontinues with step 450. Otherwise, processing proceeds with step 430.

Importantly, the upstream video may or may not contain previouslyencoded data, such as logical address links, in line 21 of the VBI. Eachcontent provider, therefore, is a potential re-encoding point along thedistribution path. At step 430, the existing data is extracted from thecaptioning data channel or the text service channel of the video signal.Subject to certain bandwidth limitations, the content provider then,embeds one or more logical address links into a captioning or textservice packet of the video signal (step 440).

Finally, at step 450, the video signal is transmitted to the nextdownstream receiving device(s). This process may be repeated duringvideo signal processing at each point along the video signaldistribution path.

Reception and Processing of Logical Address Links

Logical address link enabled receiving devices, such as a set-top box10, are able to receive and process logical address links embedded inline 21 of the VBI of an NTSC video signal. FIG. 5 is a flow diagramillustrating logical address link reception processing according to oneembodiment of the present invention. At step 510, a broadcast videosignal, such as an NTSC video signal, is received. Video data extractedfrom the broadcast video signal is passed through to the display device,e.g., a TV 12 or other display device, such as a computer monitor, forpresentation to the viewer.

Encoded data within a captioning or text service channel of the videosignal is extracted at step 520 and it is determined whether or not avalid logical address link is present (step 530). A valid logicaladdress link is one that is encoded in a predetermined syntax, such asdescribed earlier, and whose logical address and attribute/value pairsare not corrupted as determined by a comparison of a checksum generatedby the receiving device to the checksum accompanying the logical addresslink. If a valid logical address link is present, then processingcontinues with step 540. At step 540, an indication is provided to theviewer that a logical address link is associated with the TV programcurrently being viewed. According to various embodiments of the presentinvention, the indication may be visual, audible, or a combination ofone or more audible and visual indications. For example, an icon may betemporarily displayed in one of the corners of the display area.Additionally, a tone may accompany the icon's initial presentation. Itis appreciated that various other alert mechanisms are possible. In anyevent, continued reception and processing of the broadcast video signaland embedded logical address links may be achieved by returning to step510. Returning to step 530, if no valid logical address link is presentin the video signal, then processing loops back to step 510.

Combining Real-Time Logical Address Links and Batch Mode Logical AddressLinks

By providing access to both real-time logical address links and batchmode logical address links, the advantages of both can be enjoyed.Because batch mode logical address links are known in advance, theclient system may pre-fetch the resources associated with the logicaladdress links and cache them for quicker retrieval. However, batch modelogical address links are limited in that they may be outdated by thetime a program is aired. For example, a sporting event may go intoovertime and overlap a previously designated time slot for anotherprogram. In this case, one or more batch mode logical address links mayno longer be accurate. This problem may be remedied by employing logicaladdress link merging logic to selecting between previously stored batchmode logical address links and real-time logical address links accordingto predefined rules as discussed further below. The situation involvingoutdated batch mode logical address links illustrates one of theadvantages of real-time logical address links. Since real-time logicaladdress links do not need to be scheduled as far in advance as batchmode logical address link, real-time logical address links may be moreappropriate for certain content. For example, if a logical address linkis to be associated with a commercial sponsor, it is useful to transporta logical address link in the VBI or the video signal during theadvertisement rather than employing a batch mode logical address linkand hoping the commercial will be presented at a particular time.

FIG. 6 conceptually illustrates how real-time logical address links andbatch mode logical address links may be combined according to oneembodiment of the present invention. Batch mode logical address linksoriginate from EPG data suppliers 640, such as TV Data, Start Sight,Tribune Media Service (TMS), WebTV Networks, Inc., and the like. The EPGdata suppliers 640 may provide TV listings and related batch modelogical address links to a server 650. The TV listing informationtypically contains at least program start times, program end times, anda station identifier. Depending upon the EPG data supplier, more or lessinformation may be provided.

The server 650 maintains an EPG database 655 by receiving EPGinformation from multiple sources (potentially each in a differentformat) and translating the information into a common format. Accordingto one embodiment, the server 650 may add further batch mode logicaladdress links to those already present in the EPG information receivedfrom the EPG data suppliers 640. In any event, the batch mode logicaladdress links are transmitted to the client 630 periodically or uponrequest by the client 630.

Real-time logical address links originate from various video and contentsuppliers 610, such as the program producer, the broadcaster, the localaffiliate, the cable/satellite distributor, commercial sponsors, etc.The real-time logical address links are transported by inserting themdirectly into the broadcast video signal 620 as described above.

The client 630 includes logical address link merging logic 637 and alocal EPG database 635. The logical address link merging logic 637 mayrepresent one or more software routines that implement predefined rulesto facilitate the selection between real-time and batch mode logicaladdress links. In some circumstances, it may be appropriate to replace abatch mode logical address link with a real-time logical address link.In other situations, it may be convenient or make more sense tosupplement existing batch mode logical address links with newly receivedreal-time logical address links.

An exemplary method of combining real-time and batch mode logicaladdress links will now be described with reference to FIG. 7. At step710, batch mode logical address links are received by the viewer'sclient system. Preferably, the batch mode logical address links arereceived prior to any relevant TV broadcast. It is appreciated that manydistribution mechanisms may be employed. For example, the batch modelogical address links may be distributed to client systems through theInternet. Alternatively, EPG data including batch mode logical addresslinks may be distributed in electronic form on a computer readablemedium, such as a CD-ROM or diskette. Regardless of the distributionmechanism employed, in the embodiment depicted, the batch mode logicaladdress links are stored in an EPG database local to the viewer's clientsystem (step 720). Subsequently, at step 730, during the broadcast of avideo signal, one or more real-time logical address links may bereceived (embedded in line 21 of the VBI, for example). At step 740, thelogical address link status for the current TV program is determined. Inthe embodiment depicted, if more than one type of logical address linkis available, then processing continues with step 750. However, if onlyone type of logical address link is available, then processing bypassesstep 750 and continues with step 760. When no logical address links areavailable, then processing continues back at step 730. In alternativeembodiments, the status and availability of batch mode logical addresslinks may be determined once per program prior to step 740. In thismanner, indications of available logical address links may be presentedto the viewer at appropriate times without having to continually accessthe local EPG database.

At step 750, the logical address link merging logic 637 chooses betweenthe available logical address links based upon predefined rules. Thelogical address link merging logic 637 may choose to present to the userboth logical address links, only the real-time logical address link, oronly the batch mode logical address link. It is contemplated that batchmode logical address links may include links to information of generalinterest to the viewer while real-time logical address links may includelinks to more specific information. For example, EPO information mayinclude a link to a Seinfeld fan club home page or other resource ofgeneral interest to Seinfeld viewers. In contrast, the real-time logicaladdress links received during the Seinfeld program may contain linksrelevant to the particular Seinfeld episode. In this example, since thereal-time logical address links and the batch mode logical address linksdo not interfere with one another, both may be presented to the viewer.

In one embodiment, a “priority” attribute may accompany real-timelogical address links to facilitate this decision making process. Onepriority value may indicate that the real-time logical address linkdefers to the batch mode logical address link (if one exists), anothervalue may indicate the real-time logical address link overrides anyexisting batch mode logical address links, and a third value mayindicate that the particular real-time logical address link may coexistwith any batch mode logical address links that may reside in the localEPG database 635.

After a choice has been made between the various merging options, atstep 760, an indication that a logical address link is available isprovided to the viewer. The merging of batch mode and real-time logicaladdress links may continue by looping back to step 730.

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

1. A method within a system that includes a set top box capable ofreceiving content and television programming, the method for integratingthe content concurrently with the television programming, the methodcomprising: prior to receiving the television programming, retrievingelectronic program guide (EPG) data from a server, wherein the EPG dataincludes batch links associated with the television programming andwherein the batch links are associated with a predetermined timeinterval during which they are valid; storing the batch links in adatabase local to the system; after having stored the batch links,receiving the television programming; while receiving the televisionprogramming, extracting at least one real time link associated with thetelevision programming from a data channel associated with thetelevision programming, the at least one real time link being valid fora predetermined time interval commencing at the time of receipt;determining a logical address link status for the televisionprogramming, by determining whether the at least one real time link andthe batch links are both valid for some common time interval; during adisplay of a program included in the television programming, identifyingat least one link from the batch links and the at least one real timelink; providing notification concurrently with the display of theprogramming that the at least one link has been identified; accessingcontent associated with the identified at least one link; and displayingconcurrently with the programming the content accessed through theidentified at least one link.
 2. A method as defined in claim 1, whereinretrieving electronic program guide data occurs before the programincluded in the television programming begins.
 3. A method as defined inclaim 1, wherein identifying at least one link further comprises an actof selecting the at least one link from a plurality of links accordingto predefined rules.
 4. A method as defined in claim 1, wherein the atleast one real time link has a priority over the batch links.
 5. Amethod as defined in claim 1, wherein the batch links are URLs andwherein the at least one real time link is a URL.
 6. A method as definedin claim 1, wherein identifying at least one link further comprises anact of excluding batch links that have expired.
 7. A method as definedin claim 1, wherein providing notification further comprises an act ofeither providing both an audible notification and a visual notification.8. A method as defined in claim 1, wherein extracting the at least onereal time link from a data channel associated with the televisionprogramming comprises an act of extracting real-time links embedded inline 21 of the vertical blanking interval of the television programming.9. A method as defined in claim 1, wherein extracting the at least onereal time link from a data channel associated with the televisionprogramming comprises an act of extracting real-time links from acaptioning data channel associated with the television programming andwherein each real-time link comprises a priority attribute.
 10. A methodas defined in claim 1, wherein extracting real-time links from a datachannel associated with the television programming comprises an act ofextracting real-time links from a text service channel associated withthe television programming.
 11. A computing system that is capable ofreceiving content and television programming, the computing systemcomprising one or more computer-readable storage media havingcomputer-executable instructions for implementing a method fordisplaying content associated with a program included in the televisionprogramming, wherein the method comprises the method of claim
 1. 12. Acomputing system as defined in claim 11, wherein extracting the at leastone real time link from a data channel associated with the televisionprogramming comprises an act of extracting real-time links embedded inline 21 of the vertical blanking interval of the television programming.13. A computing system as defined in claim 11, wherein extracting the atleast one real time link from a data channel associated with thetelevision programming comprises an act of extracting real-time linksfrom a captioning data channel associated with the televisionprogramming.
 14. A computing system as defined in claim 11, whereinextracting the at least one real time link from a data channelassociated with the television programming comprises an act ofextracting real-time links from a text service channel associated withthe television programming.
 15. A computer program product for acomputing system that is capable of receiving content and televisionprogramming, the computer program product comprising one or morecomputer-readable storage media having computer-executable instructionsfor implementing a method for integrating the content concurrently withthe television programming, the method comprising the method of claim 1.16. A computer program product as defined in claim 15, whereinidentifying at least one link further comprises an act of selecting theat least one link according to predefined rules from a set comprising atleast one batch link and the at least one real time link.
 17. A computerprogram product as defined in claim 15, wherein the batch links are URLsand wherein the at least one real time link is a URL.
 18. A computerprogram product as defined in claim 15, wherein extracting the at leastone real time link from a data channel associated with the televisionprogramming comprises an act of extracting real-time links embedded inline 21 of the vertical blanking interval of the television programming.19. A computer program product as defined in claim 15, whereinextracting the at least one real time link from a data channelassociated with the television programming comprises an act ofextracting real-time links from a captioning data channel associatedwith the television programming.
 20. A computer program product asdefined in claim 15, wherein extracting the at least one real time linkfrom a data channel associated with the television programming comprisesan act of extracting real-time links from a text service channelassociated with the television programming.